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Youre still too smart.:urg:
 

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SixSick6 said:
max rpm is roughly 180K at 2.8 Pr which you wouldn't want to go anywhere near. At 6K (engine) you'd be close to 160K (choke) and off the chart if it actually held 10 psi till redline.
At my altitude you don't have to get near that PR to bust the shaft in 2. Try half.
 

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rebel - Pr (pressure ratio) is the ratio of the PCO (Pressure Out of the Compressor = Boost + Atmospheric Pressure + Intercooler Pressure Drop) to atmospheric Pressure. So...

Pr=
Boost + Atmospheric Pressure + Intercooler Pressure Drop/
Atmospheric Pressure

The equation factors in your altitude, but only the atm pressure part - air density still has an effect, but it should be pretty close. What is your atm pressure up there anyway?
 

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n2o_matt said:
What is your atm pressure up there anyway?
Air density decreases 2.9 - 3.0% per 1000 ft, Bwandon is at 5,900 ft, call it 6. At 9,000 ft, atmosphere drops from 14.5 to 10.5

Pr loss would be atmosphere-altitude, 14.5-10.5=4.5

Then you'd do pressure loss/atmosphere to equal a percetage of total loss.
4.5/14.5=31% at 9,000 ft
 

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n2o_matt said:
rebel - Pr (pressure ratio) is the ratio of the PCO (Pressure Out of the Compressor = Boost + Atmospheric Pressure + Intercooler Pressure Drop) to atmospheric Pressure. So...

Pr=
Boost + Atmospheric Pressure + Intercooler Pressure Drop/
Atmospheric Pressure

The equation factors in your altitude, but only the atm pressure part - air density still has an effect, but it should be pretty close. What is your atm pressure up there anyway?
11 psi.

I prefer the practical approach over theory, it is what affects you in the end. Me and my buddy went through 6 stock turbos. Every one busted the shaft in 2.

With no wastegate line connected the best it could muster is 9 psi on either of our cars. Sometimes it would get a spike to 10-12 and thats when the shaft met its demise.
 
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